We spend around a third of our lives asleep - but how much do we really understand about what happens when we close our eyes?

In this revealing and entertaining investigation into the science of sleep, celebrated chef and restaurateur Al Brown becomes a human guinea pig. Plagued by years of poor sleep, Al submits himself to sleep laboratories, medical tests and experiments, as leading scientists investigate what his nights reveal about his brain, body and health.

From circadian rhythms and sleep deprivation to insomnia, sleep apnoea and the booming business of sleep aids, Al tests the science behind the claims and discovers what really helps us sleep better. Funny, fascinating and highly relatable, this film reveals why sleep matters - and what happens when we don't get enough of it.